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The rufous bristlebird (Dasyornis broadbentii) is a ground-dwelling songbird - VCE - SSCE Biology - Question 5 - 2017 - Paper 1
Question 5
The rufous bristlebird (Dasyornis broadbentii) is a ground-dwelling songbird. The rufous bristlebird is found in gardens near thick, natural vegetation and builds ne... show full transcript
Worked Solution & Example Answer:The rufous bristlebird (Dasyornis broadbentii) is a ground-dwelling songbird - VCE - SSCE Biology - Question 5 - 2017 - Paper 1
Step 1
Define the term 'gene flow' and explain whether gene flow is likely to occur between these two populations.
Answer
Gene flow refers to the movement of alleles between populations through interbreeding. It occurs when individuals from different populations mate and produce offspring, allowing genetic material to mix. In the case of the rufous bristlebird, gene flow is unlikely to occur between Population A and Population B due to the significant distance of over 200 km separating the two populations. Given that the bristlebird is a weak flyer and prefers thickets, it is improbable that individuals from one population would migrate to the other and interbreed.
Step 2
Both of the rufous bristlebird populations in Victoria are small.
Answer
A small population size can result in limited gene pool diversity, which may pose significant survival challenges. Reduced genetic variation limits the chance of favorable traits being present in the population, and if faced with environmental changes or threats, the population could struggle to adapt. For example, if a predator is introduced, the genetically similar individuals in a small population may be unable to effectively respond to this threat, increasing the risk of extinction. Additionally, inbreeding can lead to an increased chance of genetic diseases, further compounding survival issues.